The purpose of the Animal Biohazard Containment (ABC) Core Facility is to provide support for AIDS-related mouse work requiring biosafety level 2 or 3 containment. Specifically, this will include work with chimeric SCID mice transplanted with human hematolymphoid tissue. These animals are susceptible to infection with the human immunodeficiency virus type 1 (HIV-1). Long-range plans for the use of the ABS Core Facility also include studies with other pathogens, including Epstein-Barr virus, influenza virus, and other agents causing opportunistic infections. The ABS Core Facility will allow in vivo studies aimed at elucidating pathogenesis and therapy of HIV-1 as well as pathogens that play an important role in opportunistic infections seen in AIDS patients. The ABC Core Facility gives the DFCI investigators the opportunity to extend important findings made in vitro to animals and to test new hypotheses in vivo.